Rapid frame-rate wireless imaging system
A method for defining the shape of a radiation beam that is directed toward a subject and to a free-standing imaging detector detects the position and orientation of the imaging detector relative to a radiation source, then adjusts an aperture that lies in the path of the radiation beam to shape the beam for incidence on a predetermined area of the detector according to the detected imaging detector position. The radiation source is energized to emit the shaped radiation beam and the image data about the subject is acquired from the imaging detector.
Latest Carestream Health, Inc. Patents:
- Antimicrobial housing for digital detector
- Extremity imaging apparatus for cone beam computed tomography
- Real-time image processing for fluoroscopic imaging
- Virtual projection images for tomosynthesis artifact reduction
- Method and apparatus for automatic touchless wireless charging of mobile x-ray cart detectors and accessories
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a 371 national stage application of earlier filed international application Serial No. PCT/US2013/062823, filed on Oct. 1, 2013 entitled “RAPID FRAME-RATE WIRELESS IMAGING SYSTEM”, in the names of Sehnert et al., which itself claims the benefit of earlier filed Provisional Application Ser. No. 61/708,846, filed on Oct. 2, 2012, entitled “RAPID FRAME-RATE WIRELESS IMAGING SYSTEM”, in the names of Sehnert et al., all of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The invention relates generally to the field of medical imaging; more particularly to a method for control of components of a portable x-ray fluoroscopic imaging apparatus with a detachable x-ray detector.
BACKGROUND OF THE INVENTION
Fluoroscopy provides near real-time visualization of internal anatomy of a patient, with the ability to monitor dynamic processes, including tracking the relative motion of various types of features such as probes or other devices, fluids, and structures. Fluoroscopy is used, for example to help in diagnosis and to position the patient for subsequent image recording or to position and manipulate various types of devices for interventional procedures.
The block diagram of
To reduce the exposure of the patient to ionizing radiation, conventional fluoroscopy practices use the collimator 22 to limit the size of the exposure field as much as possible. Adjustments to collimator 22 are made using an initial “scout image” to ascertain how well the radiation beam is centered and how much adjustment of the collimators can be allowed in order to direct radiation to the region of interest (ROI) for a particular patient 14. The practitioner views the scout image and makes adjustments accordingly, then begins the active imaging sequence for fluoroscopy. This procedure is time-consuming and approximate, sometimes requiring repetition of the adjustment to correct for error. Moreover, movement of the patient or ongoing progress of a contrast agent or probe or other device can cause the ROI to shift, requiring that the imaging session be repeatedly paused in order to allow for collimator readjustment.
As digital radiography (DR) imaging receivers steadily improve in image quality and acquisition speed, it is anticipated that these devices can be increasingly employed not only for conventional radiography imaging, but also for fluoroscopy applications, effectively eliminating the need for the dedicated image intensifier hardware used with conventional fluoroscopy systems such as that shown in
SUMMARY OF THE INVENTION
An aspect of this application is to advance the art of medical rapid frame-rate wireless imaging (e.g., fluoroscopy).
Another aspect of this application to address in whole or in part, at least the foregoing and other deficiencies in the related art.
It is another aspect of this application to provide in whole or in part, at least the advantages described herein.
Another aspect of the application is to provide methods and/or apparatus by which medical rapid frame-rate wireless imaging can be provided.
Another aspect of this application is to address the need for improvements in providing rapid-frame rate imaging from a portable system.
According to an aspect of the present invention, there is provided a portable radiographic imaging apparatus comprising:
- a wheeled transport frame; and
- a support arm mounted on the frame and having a fixed end that is coupled to a radiation source and, opposite the fixed end, a retractable end, wherein the retractable end seats an imaging detector when the retractable end is extended outward from the frame and retracts into the support arm in a retracted position;
- wherein the imaging detector is removable from the retractable end for free-standing operation with the support arm in the retracted position.
According to an alternate aspect, there is provided a method for defining the shape of a radiation beam that is directed toward a subject and to a free-standing imaging detector, the method comprising:
- a) detecting the position and orientation of the imaging detector relative to a radiation source;
- b) adjusting an aperture that lies in the path of the radiation beam to shape the beam for incidence on a predetermined area of the detector according to the detected imaging detector position;
- c) energizing the radiation source to emit the shaped radiation beam; and
- d) acquiring image data about the subject from the imaging detector.
According to an alternate aspect, there is provided a portable radiographic imaging apparatus comprising:
- a support arm mounted on a frame and having a fixed end that is coupled to a radiation source array that has two or more radiation sources that are individually energizable to emit a radiation beam toward a detector;
- a switching actuator that is energizable to align the radiation beams from each of the two or more radiation sources along the same optical path;
- at least one radiation source temperature sensor element that provides a signal that is indicative of temperature near the energized radiation source; and
- a processor that monitors the signal from the at least one radiation source sensor element and controls at least energization of the two or more radiation sources according to the monitored signal.
These objects are given only by way of illustrative example, and such objects may be exemplary of one or more embodiments of the invention. Other desirable objectives and advantages inherently achieved by the disclosed invention may occur or become apparent to those skilled in the art. The invention is defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of the embodiments of the invention, as illustrated in the accompanying drawings. The elements of the drawings are not necessarily to scale relative to each other.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
The following is a detailed description of the preferred embodiments of the invention, reference being made to the drawings in which the same reference numerals identify the same elements of structure in each of the several figures.
Where they are used, the terms “first”, “second”, and so on, do not necessarily denote any ordinal, sequential, or priority relation, but are simply used to more clearly distinguish one element or set of elements from another, unless specified otherwise. The term “pixel” has its standard meaning, referring to a picture element, expressed as a unit of image data.
In the context of the present disclosure, the terms “viewer”, “operator”, and “user” are considered to be equivalent and refer to the viewing practitioner or other person who views and manipulates an x-ray image, such as a fluoroscopic image, on a display monitor. A “viewer instruction” can be obtained from explicit commands entered by the viewer on the surface of the display or may be implicitly obtained or derived based on some other user action, such as setting up or initiating an exposure or making a collimator adjustment, for example.
In the context of the present invention, the terms “near video rate” and “near real-time” relate to the response time for image data display. For fluoroscopy, because of detector response limitations and because it is beneficial to help reduce radiation levels, what is considered real-time or near-real-time video presentation is generally at a slower frame refresh rate than rates used for conventional video imaging. Thus, in the context of fluoroscopy imaging for example, a useful “near real-time” refresh rate is at least about 1 or more frames per second.
The term “highlighting” for a displayed feature has its conventional meaning as is understood to those skilled in the information and image display arts. In general, highlighting uses some form of localized display enhancement to attract the attention of the viewer. Highlighting a portion of an image, such as an individual organ, bone, or structure, or a path from one chamber to the next, for example, can be achieved in any of a number of ways, including, but not limited to, annotating, displaying a nearby or overlaying symbol, outlining or tracing, display in a different color or at a markedly different intensity or gray scale value than other image or information content, blinking or animation of a portion of a display, or display at higher resolution, sharpness, or contrast.
Exemplary embodiments of the application can enable the use of a digital radiography (DR) receiver as the digital image receiver for receiving radiation in the fluoroscopy system and for generating, processing, and transmitting the received image data, as image pixels (picture elements), to a display apparatus for fluoroscopic display.
An aspect in obtaining processed image data of the subject at near video rates relates to the need for both high-speed data access between DR receiver 50 and image processing unit 58 and high data transmission rates from image processing unit 58 to host processor 52 (
One method for reducing the bulk amount of data that must be transferred determines the differences between two successive frames and provides only the data that is indicative of the difference. The block diagram of
Continuing with the sequence shown in
With respect to the sequence described with reference to
The difference scheme used in the sequence described with reference to
Image data compression techniques can also be lossless or lossy and embodiments of the application can employ both types of compression for different types of image content to reduce data transferred.
Regardless of the method that is employed for image compression and transmission, region of interest 70 is identified, relative to the image area of the digital detector or receiver, DR receiver 50 (
Some type of viewer instruction or action is used to define the region of interest.
User tracing or placement of a shape that defines a region of interest relative to a basis image can be performed in a number of ways, using standard user interface tools and utilities, that include a touch screen or use of a computer mouse or stylus or other pointer.
The example of
The example illustrated in
According to an alternate embodiment of the present method/apparatus, the operator can adjust collimator blade positions and observe blade repositioning directly on the display screen, allowing the system to adopt and change ROI boundaries according to blade settings. To obtain suitable coordinates for ROI identification, the imaging system detects the positions of collimator blades, and translates this positional information into corresponding coordinates on the detector for ROI identification.
Thus, in various ways, an ROI is identified, wherein the ROI maps to, or relates to, the image area of the digital detector of the imaging system. The viewer instruction that identifies/defines the ROI may be explicitly entered using the basis image as previously described, or may be inferred from a collimator or other adjustment. Alternately, the viewer instruction may simply be a command or instruction to prepare for obtaining images, thus prompting the imaging system to use a default ROI definition based on the type of image being obtained or based on sensed settings of the collimator, for example.
Once region of interest 70 is defined on the basis image, the viewer can enter an explicit instruction that indicates completion of this process. Alternately, the given settings are used automatically and exposure can begin. The specified region of interest settings are maintained until specifically adjusted by the viewer.
The displays 710, 710′ can implement or control (e.g., touch screens) functions such as generating, storing, transmitting, modifying, and printing of an obtained image(s) and can include an integral or separate control panel (not shown) to assist in implementing functions such as generating, storing, transmitting, modifying, and printing of an obtained image(s).
For mobility, the mobile radiographic apparatus 700 has one or more wheels 715 and one or more handle grips 725, typically provided at waist-, arm-, or hand-level, that help to guide the mobile radiography apparatus 700 to its intended location. A self-contained battery pack (e.g., rechargeable) typically provides source power, which can reduce or eliminate the need for operation near a power outlet. Further, the self-contained battery pack can provide for motorized transport.
For storage, the mobile radiography apparatus 700 can include an area/holder for holding/storing one or more digital detectors or computed radiography cassettes. The area/holder can be storage area 730 (e.g., disposed on the frame 720) configured to removably retain at least one digital radiography (DR) detector. The storage area 730 can be configured to hold one or more detectors and can also be configured to hold one size or multiple sizes of detectors.
Mounted to frame 720 is a support column 735 that supports an x-ray source 740, also called an x-ray tube, tube head, or generator that can be mounted to the support column 735. In the embodiment shown in
As shown in
According to exemplary embodiments of the application, the first display 710 and the second display 710′ can provide information such as but not limited to: (i) general information such as date, time, environment conditions, and the like; (ii) unit information such as model serial number, operating instructions, warning information, and the like; (iii) patient data, such as patient name, room number, age, blood type, and the like; (iv) indicators such as but not limited to cart power/battery indicators, detector status (e.g., on/off), wireless signal strength/connectivity, grid alignment aides, cart diagnostics and/or (v) imaging/procedure information, such as the exam type, exposure information, and the like.
According to embodiments of the application, the first display 710 and the second display 710′ can provide capabilities/functionality to the mobile radiography apparatus 700 such as but not limited to: (i) view and/or change x-ray exposure parameters, tube/generator/technique settings; (ii) view and/or change image information, such as a list of views (e.g., body part & projection) to perform for the patient, relevant information about those views, the ability to select a view to perform, and an x-ray image of an acquired view; (iii) display and/or change patient information, such as: Patient Name, Room number, Patient ID, date of birth (e.g., to confirm that the correct patient); (iv) display and/or change a Patient Worklist, such as a list of exams to perform and allow the user to select an exam (In one embodiment, such a patient worklist can be automatically updated (e.g., synchronized to a master/hospital/doctor worklist) using a wired or wireless network/connection. In one embodiment, the mobile radiography apparatus 700 can highlight/indicate new exams (e.g., on the second display 710′) upon receipt of the scheduled examination); (v) display generator/source current values and controls to change those values, such as: kVp, mA, mAs, Time, ECF, focal spot, collimator, filter, AEC, grid; (vi) display detector selection and allow the technician to select/activate a different detector; (vii) display recently acquired images and allow editing of those images, exemplary acquired (e.g., recently) or previous images can be displayed full size, partial size or with corresponding image information; (viii) display previously acquired images (e.g., related prior images of a patient) and allow editing of those images; or (ix) display a video of what is in front of the mobile radiography apparatus 700 during transport, e.g., using a video camera located on the other side (e.g., front side of a mobile x-ray imaging apparatus 700).
In the context of the present disclosure, an original or primary image of a subject that is acquired by a system of the present application can include raw image data or may be image data that is automatically pre-processed by the x-ray system itself (so that the raw data is not directly available to users of the system). This can be termed the “primary”, “original”, or “acquired” image of the subject and can include image data from scanned film, from a computed radiography (CR) imaging system, or from a digital radiography (DR) system, for example.
In the context of the present disclosure, a “prior image” is an image for a patient that was acquired during a previous visit, and preferably, the prior image can be relevant (e.g., same body part) to a current examination to be performed, which will result in a primary image. The capability to view prior images before a current examination to be performed (e.g., for the same patient) including information about imaging techniques used in the prior images can help the technician to obtain a high quality image for the current examination. In one embodiment, a “copy technique” operator action can import specific exposure settings from a selected (e.g., desirable, ideal) prior image among a plurality of prior images for the technician. Prior images can also be related to an identifiable condition or an area of interest in the object to be imaged. Embodiments of systems and/or methods for management and display of prior images can provide a controllable association between prior images and can provide tools for management of that association.
Conventional solutions for image storage and retrieval and for association of multiple images obtained for the same patient employ the PACS (Picture Archiving and Communication System) and various conventional database tools. Thus, as described herein, the PACS is an image store accessible to a radiographic imaging system or an agent thereof to retrieve images therefrom. In one embodiment, the PACS can implement the Digital Imaging and Communications in Medicine (DICOM) data interchange standard.
The schematic diagram of
As shown in
Still referring to
Primary image 932 can be provided to one or more logic processors 922, 924 that each can perform some type of image processing and analysis operation before the primary images 933 and 934 can be stored in the PACS 920 along with acquired primary image 932. As shown in
In one embodiment, the mobile radiography apparatus 700 (
For medical diagnosis, subsequent medical x-ray images can be compared by technicians/doctors/medical personnel to prior medical x-ray images of the same patient. It is preferable that the x-ray images different in time be obtained under the same conditions (e.g., exposure parameters). However, when different equipment, technicians, or medical facilities take the plurality of x-ray images there can be significant differences in the obtained x-ray images.
According to embodiments of the application, prior images can be reviewed before the imaging technician executes a current examination. The technician can “select prior parameters” from a desirable prior image and have a mobile x-ray unit be automatically set to the same parameters as the indicated desirable prior image.
Since prior images can be 10 MBs, 20 MBs, 30 MBs or more of data, and 10, 20 or more than 50 prior images may be related to a current examination, the prior images can constitute a large quantity of data or network traffic to transmit the prior images to the portable DR imaging apparatus 910. Pre-fetching of the prior images can be used to reduce network traffic or to timely provide prior images to the portable DR imaging apparatus 910 for display of a selected prior image. Pre-fetching (e.g., obtaining in advance of their use or need) images can be stored at the portable DR imaging apparatus 910 prior to a technician taking the unit 910 on their “rounds” to capture new/further images. Beneficially, pre-fetching can allow the technician to download the prior images over the wired network (e.g., limited access but faster) compared to a download over the wireless network available throughout the medical facility. The parameters (e.g., kVp level setting) of the pre-fetched prior images can be used to capture the new images for a current exam.
Embodiments of the application can include features of a mobile radiographic unit directed to fluoroscopy imaging.
According to embodiments of the application, the first display 710 and/or the second display 710′ (
According to embodiments of the application, the first display 710 and/or the second display 710′ can provide prior image display” feature/GUI with capabilities/functionality such as but not limited to: (i) display of a prior image itself; (ii) determining the size of the lung field in the image or determining prior image orientation (e.g., landscape vs. portrait) and determining for the same whether the user wants/selects consistent detector location & orientation between images, or the user indicates the prior was inadequate and a change should be made; (iii) displaying exposure technique information; (iv) matching current exposure techniques with prior images; (v) displaying SID (Source to Image Distance); (vi) matching SID with prior images; (vii) displaying angle measurements such as but not limited to patient angle—supine, upright or some angle in-between, X-Ray tube angle, X-Ray tube angle to patient angle—usually 90 but not always; (viii) matching angle with prior angle; (ix) displaying grid information such as but not limited to: was a grid used, grid ratio, transverse vs. longitudinal, recommended SID/SID range for that grid; (x) matching grid/no-grid and grid type with the prior; (xi) showing the prior exposure index to indicate if too much or too little exposure was used in the prior image; (xii) consistent rendering between prior image and new one (e.g., see below); (xiii) image capturing device or detector for the prior image (e.g., manufacturer, model, device name, etc.). There are variations in the quality (e.g., ISO speed, sensitivity) of detectors (e.g., better detectors require less dose) and also variations in the method different manufacturers use to calculate Exposure Index. Thus, knowing the image capturing device can benefit the technician.
Certain exemplary system and/or method embodiments described herein can provide fast frame-rate wireless cassette-sized x-ray image detectors powered by an internal battery. Mobile x-ray acquisition control system and/or method embodiments can be configured with a wireless cassette-sized x-ray image detector that is capable of capturing x-ray images at a rapid frame rate. Generally, the term fast or rapid frame-rate x-ray imaging is used herein instead of fluoroscopy because exemplary radiographic acquisition can serve a more general purpose, e.g. dual energy, tomosynthesis, fluoroscopy, and the like. Certain exemplary embodiments described herein can provide mobile x-ray acquisition control systems that use a rigid c-arm or other support arm where the detector is detachable. In one embodiment, when detector is detached, the c-arm unit's detector arm is removable or the c-arm unit's detector arm retracts into the upper arm or housing of the unit.
Certain exemplary embodiments described herein can provide in-room x-ray acquisition control system capable of fast frame-rate x-ray imaging with a wireless x-ray image detector. Additional exemplary embodiments described herein can provide an x-ray acquisition control system comprising a portable, e.g. hand-held, x-ray tube/generator, a wireless x-ray image detector and a tube/generator mounting mechanism that enables the tube to be aligned with the detector.
In one embodiment, x-ray sources on the acquisition control system may provide continuous or pulsed operations. In one embodiment, x-ray image detector can be used while docked (e.g., not detached) to an acquisition control system. In one embodiment, a docked x-ray image detector can connect to a port that: supplies power to the detector; charges the battery in the detector; enables wired communication between the detector and the acquisition control system; enables transmission of data between the detector and the acquisition control system; or any combination of the above embodiments. Alternatively, an x-ray image detector may be tethered to the acquisition control system.
In one embodiment, an acquisition control system has a means to manually align the x-ray source (tube assembly) to the x-ray image detector using visual feedback means or audio feedback means. In one embodiment, the acquisition control system and x-ray image detector are configured with devices to enable relative geometric measurements to be made, e.g. source to detector distance, the angles between the normal of the detector and the primary x-ray beam. The acquisition control system can also include a means to automatically align the x-ray source to the x-ray image detector. Alignment is not restricted to perpendicular configuration, but includes x-ray impingement at various angles with respect to the axes of the detector.
Certain exemplary system and/or method embodiments can provide acquisition control that can automatically select the appropriate x-ray source from an array of x-ray sources and to align the activated x-ray source to achieve the desired projection angle. (This can negate the need for physical motion of the x-ray source). Alignment is not restricted to perpendicular configuration, but includes x-ray impingement onto the x-ray image detector surface at various angles with respect to the axes of the detector. In one embodiment, exemplary acquisition control systems can have the ability to automatically collimate (e.g., symmetric or asymmetric) the x-ray beam in order to restrict the emitted beam to the surface area of the detector.
In one exemplary embodiment, there is a switch that operates the acquisition control system. Engaging the switch initiates the rapid frame-rate imaging process.
Certain exemplary system and/or method embodiments can provide an AEC/ABC whose functionality is derived from the pixel data in the raw image, a sub-region of the raw image, a sub-sampling of the raw image; the AEC functionality is derived from dedicated radiation sensors that are integral to the pixel substrate but different in design from the pixel imaging sensors; the AEC functionality is derived from x-ray sensors internal to the detector housing but separate from the pixel substrate (e.g., a thin ion chamber placed inside the detector housing); the AEC functionality is derived from a sensor that snaps onto the exterior of the detector.
Exemplary system and/or method embodiments can include an x-ray grid that may be attached onto the x-ray image detector. The grid can be configured with a physical or electronic marker that can be identified and recognized by the acquisition control system. The identifying information, along with geometric information (SID, angulations, etc) can be used by a component of the acquisition control system to ensure the x-ray source is properly aligned with the grid before the x-ray source can be fired. Proper alignment of the system may be a visual or audio signal. Certain exemplary embodiments can provide x-ray image detectors configured with a phase lock synchronization mechanism that can synchronize the exposure integration and image signal readout from the detector when the x-ray source is pulsed.
In one embodiment, a x-ray image detector stand can be included that is configured with a physical or electronic marker that can be identified and recognized by the imaging system. The identifying information, along with geometric information (SID, angulations, etc) is used by a component of the acquisition control system to ensure the x-ray source is properly aligned with the detector before the x-ray source can be fired. The component can be a visual or audio signal. One exemplary acquisition control system can be configured with independently movable collimator blades.
Certain exemplary acquisition control system and/or method embodiments can be configured with temperature sensors that monitor the temperature of the x-ray tube assembly and the x-ray image detector. In one embodiment, temperature readings and the x-ray techniques can be used to provide feedback to the user of how much longer the system can be used before it will be shut-down in order to avoid overheating. In one embodiment, x-ray image detectors can be configured with a temperature sensor and the temperature information can be used to adjust the gain-offset calibration algorithm.
Certain exemplary acquisition control system and/or method embodiments can be configured with multiple x-ray sources. Exemplary x-ray sources shall be interchangeable and have the ability to be quickly changed out in the case that the current x-ray source nears an overheated state. In another exemplary embodiment, the x-ray sources may rotate in a queue to avoid overheating. Preferably, when the x-ray sources are changed, the new x-ray source has a focal spot that is of the same size and alignment as the previous x-ray source. Certain exemplary embodiments provide redundancy (e.g., multiple x-ray assemblies) in long imaging procedures where the x-ray source is left on for long periods of time. In one embodiment, before use, the x-ray sources can be put through a tube warm up procedure. Exemplary imaging systems an/or methods can perform rapid-frame rate dual-energy imaging.
Certain exemplary acquisition control system and/or method embodiments can accept an integrated injecting system, e.g. an x-ray contrast injector. The injecting system can be synchronized with the rapid frame-rate exposures to adapt, simplify or optimize the procedural workflow.
Certain exemplary acquisition control system and/or method embodiments can accept an integrated ultrasound imager. The imaging system can provide rapid frame-rate x-ray imaging with registration and fusion with the ultrasonic imagery.
Certain exemplary acquisition control system and/or method embodiments can include the ability for a user to define an ROI on the x-ray image detector. Rapid frame-rate imaging readout can be performed exclusively on the ROI. In another embodiment, the rapid frame-rate imaging readout can be performed on both ROI and non-ROI regions, but with a different frame-rate in the non-ROI region. In one embodiment, an ROI can be physically obtained with independently movable collimator blades; the ROI may be realized on different stops of a rotating wheel that is composed of distinct regions composed of material having different radiolucency; the ROI may be realized using a continuously rotating wheel that is composed of materials having different radiolucency and that is synchronized with pulsed x-rays.
Certain exemplary acquisition control system and/or method embodiments can be configured with a synchronized contrast bolus injector that has the ability to center the x-ray source, or field of view, over the bolus injection site and to collimate the x-ray source to the x-ray image detector, or field of view; the acquisition control system has the ability to capture a diagnostic quality radiograph (i.e. a key image) when the bolus attains a specific state (e.g. the bolus reaches a specific location, or the bolus contrast has reached a plateau within the image frame, or the like). In one embodiment, acquisition control systems, configured with a synchronized contrast injector, can provide that ability to automate the acquisition of a DSA by using a lower dose setting until the desired contrast is reached within the ROI (e.g., which may be the entire detector) and to provide the ability to stop live imaging when there is less than a target amount of contrast remaining in the ROI.
In the context of the present disclosure, the term “orthogonal” or “normal” is used to describe an angular relationship of about 90 degrees+/−10 degrees or, alternately, 270 degrees+/−10 degrees. The term “parallel” describes an angular relationship of about 0 degrees, +/−10 degrees or, alternately, 180 degrees, +/−10 degrees. Angles outside these values and thus in the range from about 10 degrees to about 80 degrees are considered to be oblique.
Positive Beam Limitation
Conventional C-arm systems for fluoroscopy and for radiographic imaging in general have applied various techniques to the problem of limiting the shape of the radiation beam that passes through the subject and is incident on the imaging detector. A desired outcome of this feature, termed “positive beam limitation” is to restrict the shape of the radiation beam so that patient exposure is constrained to a region of interest (ROI) that does not exceed the bounds of the imaging detector.
For fixed-geometry imaging apparatus, calculations and methods for achieving positive beam limitation is relatively straightforward. Simple trigonometric relationships allow the shape of the beam relative to the detector to be readily calculated when the beam is directed orthogonally to the imaging detector, such as in a conventional C-arm fluoroscopy system.
Imaging apparatus having free-standing imaging detectors, as shown in
Embodiments of the application address the problem of providing positive beam limitation by sensing the position of the imaging detector relative to the radiation source, adjusting the collimator or other aperture in the path of the radiation beam to shape the beam for incidence on the detector or, more generally, on a predetermined area of the detector, and then energizing the radiation source to emit the shaped radiation beam through the subject and onto the imaging detector for acquiring image data. Exemplary methods of embodiments of the application can be advantageous for imaging modes such as fluoroscopy, where the use of a free-standing detector is preferred for reasons such as for patient comfort, for reducing the need for specialized support equipment, or for improved visibility for the practitioner, for example.
The schematic block diagram of
The schematic block diagram of
In terms of the familiar Cartesian coordinate system for 3-D positioning, radiation source 804 can be considered to be the origin, with coordinates (0, 0, 0), as shown in
There are a number of different techniques for accurate detection of free-standing detector 802 position and the locations of corner points P1, P2, P3 that also indicate orientation, as well as other detector features relative to source 804 when detector 802 is positioned behind the patient or other subject. According to an embodiment of the application, shown in
Still other approaches for accurate detection of free-standing detector 802 position and the locations of corner points P1, P2, P3 utilize a pattern of signals that are transmitted between locations on detector 802 and processor 830. Signals for positioning can be transmitted by processor 830, by collimator 810, or by transmitter circuitry that is coupled directly to detector 802. The signals can be wireless signal types, such as audio or radio-frequency (RF) signals. According to an alternate embodiment of the application, tilt sensors or accelerometers are coupled to detector 802 and used for position sensing. According to another alternate embodiment of the application, global positioning system (GPS) components are used to provide signals to processor 830 for detector 802 position sensing and reporting. Any of a number of possible arrangements of sensing element 834 or one or more transmitter elements 836 can be used and sensing elements 834 and transmitter elements 836 can be optionally coupled to the collimator 810, to detector 802, or to both, as indicated in
Positive beam limitation uses the positional information obtained from detector 802 and the capability to control the shape of the aperture 824 from collimator 814 or 820 to shape the emitted radiation so that shaped emitted radiation is sufficient for or best suits particular clinical or diagnostic goals, including use in fluoroscopy and other imaging modes that obtain one or more radiographic images during an imaging session. In some cases, this entails constraining radiation to a portion of the detector 802 that provides images of a region of interest (ROI); in other cases, this entails constraining radiation so that it matches or closely approximates the outline of the detector 802 or does not exceed the outline of the detector along any edge of detector 802; in still other cases, this entails constraining radiation so that the full detector is exposed.
The schematic diagram of
The schematic diagram of
When radiation is directed to the detector 802 at an oblique angle, as was shown in
Retractable C-Arm and Detachable Detector
As shown in
As shown in
According to an embodiment of the application, support arm 854 is a C-arm that is movable in a number of directions relative to transport frame 852 or a stationary frame. Support arm 854 is movable in the forward and reverse directions, vertically, and laterally, or side-to-side.
Configuration of Retractable End
There are a number of mechanical and/or electro-mechanical systems and/or methods that can be used to provide retractable operation of support arm 854, known to those skilled in the mechanical arts.
Timing and Synchronization
Certain exemplary embodiments according to the application can provide first communications between a detachable detector and an imaging apparatus (e.g., imaging apparatus controller) when mounted thereto and second communications (e.g., wireless) therebetween when the detachable detector is used for imaging but detached therefrom. In one embodiment, detector 802 can include built-in connectors so that power and communications ports are provided by imaging apparatus 800 hardware when detector 802 is seated in support 862. This can include connection to processor 870 in the portable imaging apparatus 800 for signal communication with processor 870. When the detector 802 is detached from support arm 854, detector 802 is capable of wired or wireless signal communication and interaction with processor 870. According to an alternate embodiment of the application, a detached detector imaging capability is not provided and only wired transmission is provided and a cable (not shown) connects detector 802 with power and with processor 870.
In the extended C-arm configuration of
According to an embodiment of the application, synchronization timing follows this sequence:
- (i) interaction between the processor 870 and detector 802 indicates that detector 802 is or will presently be ready for acquiring image data and that processor 870 is ready to energize the radiation source 804. This interaction typically requires transmission of signals in both directions between detector 802 and processor 870;
- (ii) a signal from, or directed through, processor 870 indicates the beginning and end of exposure;
- (iii) image data from detector 802 is acquired by processor 870; this may be provided automatically upon acquisition and initial processing of the data or in response to a prompting signal from processor 870.
The cycle of processes (i)-(iii) then can repeat as many times as needed. For a fluoroscopy system, for example, this cycle can be executed a number of times per second, with the image data results updated at a rapid rate and displayed (or stored or transmitted remotely).
Operator controls, such as controls available on display 864 for example, or controls 874 on support arm 854 or on suitable parts of apparatus 800, enable manipulation of the retractable end 860 so that it can be extended outward (e.g., partially or fully) for C-arm imaging or retracted for free-standing imaging, as needed. Referring to
Temperature monitoring for the x-ray source and detector can be particularly useful where imaging apparatus 800 acquires images in a repeated fashion, such as for fluoroscopy, for example.
According to an embodiment of the application, processor 870 temporarily can stop imaging operations when either the source or detector temperature exceeds given threshold values.
Certain exemplary system and/or method embodiments according to the application can provide an imaging apparatus that can use multiple, interchangeable radiographic sources.
An actuator 880 is energizable to switch between sources 804a and 804b in response to heat sensing. In a turret 886 arrangement, actuator 880 rotates the desired source 804a or 804b into position, wherein the axis of rotation extends in the direction of the radiation beam. According to an alternate embodiment of the application, switching actuator 880 is a motor or solenoid that is operatively coupled to a reflective element or other type of guide that redirects the x-ray beam. The reflective element can be switchable so that it lies in the path of either source 804a or 804b as needed, under control of processor 870.
According to an alternate embodiment of the application, manual switching of the source is also provided for pivoting the appropriate source 804a or 804b into position. An interlocking rotating pivot could be provided for automatic or manual switching.
According to another alternate embodiment of the application, radiation sources 804a and 804b are detachable, allowing removal and replacement.
Image Acquisition Management System
Certain exemplary embodiments according to the application can provide image acquisition management for a fluoroscopic imaging system including a capability to plan one or more fluoroscopic examinations and increase a likelihood such examinations can be completed. Certain exemplary embodiments according to the application can provide image acquisition management for a fluoroscopic imaging system including at least heat-capacity (e.g., temperature) limited capabilities of a radiation source, bandwidth limited communications with a wireless (e.g., detachable) detector, storage limited capability of a wireless (e.g., detachable) detector, and power (e.g., battery) limited capabilities of a wireless (e.g., detachable) detector and/or storage energy (e.g., battery) limited capabilities of a portable fluoroscopic imaging system. Thus, in one exemplary embodiment, an image acquisition management controller for a fluoroscopic imaging system, can consider or address inputs including (i) fluoroscopic procedures to be performed, (ii) expected or actual bandwidth of communications with a detector, (iii) storage capabilities of a detector (e.g., before image(s) are confirmed to be transmitted to a fluoroscopic imaging system, (iv) remaining storage energy of the wireless detector, (v) remaining heat capacity of a radiation source, and/or (vi) remaining storage energy of said fluoroscopic imaging system.
According to such exemplary inputs, certain exemplary image acquisition management controller embodiments can modify planned or current (e.g., actual concurrent) operations of a source (e.g., reduced exposure rate, reduced exposure area, reduced exposure power) to address, control or reduce temperature and/or control or increase operational life relative to one or more fluoroscopic procedures. Further, according to such inputs, certain exemplary image acquisition management controller embodiments can modify planned or current (e.g., actual concurrent) operations of a detector to lower frame-rates and/or resolution (binning) when detector battery power is low to control or increase operational life relative to one or more fluoroscopic procedures. In addition, according to such inputs, certain exemplary image acquisition management controller embodiments can modify planned or current (e.g., actual concurrent) operations of a detector to lower frame-rates and/or resolution (binning) when bandwidth is low to implement one or more fluoroscopic procedures.
In one embodiment, an image acquisition management controller for a fluoroscopic imaging system can be implemented in processor 870. In one embodiment, an image acquisition management controller for a fluoroscopic imaging system can be monitor an interventional fluoroscopic procedure having an unknown length by providing a display to an operator of a current time until the source (e.g., source 804a) or the detector 802 needs to be changed based on current source temperature and operating mode, and current battery consumption rate and operating mode, respectively. In one embodiment, a warning can be provided to plan to interchange a source (e.g., detector) or change source operations such as exposure rate (e.g., detector operations such as lower frame-rates or data transmission rates). For example, an exposure rate of the source can be decreased or slowed to extend the source lifetime to finish the interventional operation. Upon operator action, the displayed status of the source and/or detector can be updated accordingly. In one embodiment, a display can include at least time until source overheat/replacement and/or time until detector bandwidth overflow or battery replacement. In one embodiment, a detector stores all data received during an examination until confirmation is received that transmitted portions thereof have been received and acknowledged by the imaging system. Such data storage operations can be monitored as well.
In one embodiment, an image acquisition management controller for a fluoroscopic imaging system can provide planning for a plurality of planned fluoroscopic procedures. For example, an operator may have 5 examinations with corresponding image acquisition requirements to be performed in an afternoon or set time period. Accordingly, the image acquisition management controller can provide a planned source control schedule and detector operation control or power consumption control to allow a likely completion of all 5 examinations without source or detector replacement. To complicate such analysis, additional factors can be monitored by the image acquisition management controller such as a number and condition of replacement detectors, interchangeable sources, replaceable detector batteries carried by a fluoroscopic imaging system. Further, selected fluoroscopic examination location can provide a capability to charge a portable fluoroscopic imaging system battery and/or a detector battery.
In one embodiment, an image acquisition management controller for a fluoroscopic imaging system can monitor a fluoroscopic procedure (e.g., having a known or planned procedural length/data acquisition amount) to limit or control the capabilities of the imaging system based on the wireless bandwidth available, e.g. limit to lower frame-rates and/or resolution (binning) when bandwidth is low. Alternatively, an image acquisition management controller can monitor a fluoroscopic procedure (e.g., having a known or planned procedural length/data acquisition amount) to limit or control the capabilities of the imaging to the battery power of the wireless detector, e.g. limit to lower frame-rates and/or resolution (binning) when detector battery power is low. Further, an image acquisition management controller can monitor a fluoroscopic procedure to limit or control the capabilities of the source and/or detector based on a current image quality whereby image quality can be improved as desired by improving data transmission (e.g., increase frames per second (fps), reduce binning, or the like).
Certain exemplary system and/or method embodiments according to the application can provide a C-arm radiographic imaging apparatus that can use multiple, interchangeable radiographic sources. In one embodiment, multiple x-ray sources 804a and 804b (e.g., switchable head 890) can be replaced or switched responsive to a current temperature (e.g., detected by temperature sensor element 882) in order to provide more continuous or near-continuous fluoroscopic imaging. In one embodiment, before (or when) source 804a overheats to the extent that source 804a can not be used for imaging, source 804a is replaced by source 804b to increase an operational time that the apparatus (e.g., shown in
Consistent with at least one embodiment, exemplary methods can use a computer program with stored instructions that perform on image data that is accessed from an electronic memory. As can be appreciated by those skilled in the image processing arts, a computer program of an embodiment of the present invention can be utilized by a suitable, general-purpose computer system, such as a personal computer or workstation. However, many other types of computer systems can be used to execute the computer program of the present invention, including an arrangement of networked processors, for example. The computer program for performing the method of the present invention may be stored in a computer readable storage medium. This medium may comprise, for example; magnetic storage media such as a magnetic disk such as a hard drive or removable device or magnetic tape; optical storage media such as an optical disc, optical tape, or machine readable optical encoding; solid state electronic storage devices such as random access memory (RAM), or read only memory (ROM); or any other physical device or medium employed to store a computer program. The computer program for performing one method of the application may also be stored on computer readable storage medium that is connected to the image processor by way of the internet or other network or communication medium. Those skilled in the art will further readily recognize that the equivalent of such a computer program product may also be constructed in hardware.
It should be noted that the term “memory”, equivalent to “computer-accessible memory” in the context of the present disclosure, can refer to any type of temporary or more enduring data storage workspace used for storing and operating upon image data and accessible to a computer system, including a database, for example. The memory could be non-volatile, using, for example, a long-term storage medium such as magnetic or optical storage. Alternately, the memory could be of a more volatile nature, using an electronic circuit, such as random-access memory (RAM) that is used as a temporary buffer or workspace by a microprocessor or other control logic processor device. Display data, for example, is typically stored in a temporary storage buffer that is directly associated with a display device and is periodically refreshed as needed in order to provide displayed data. This temporary storage buffer can also be considered to be a memory, as the term is used in the present disclosure. Memory is also used as the data workspace for executing and storing intermediate and final results of calculations and other processing. Computer-accessible memory can be volatile, non-volatile, or a hybrid combination of volatile and non-volatile types.
It will be understood that computer program products of this application may make use of various image manipulation algorithms and processes that are well known. It will be further understood that exemplary computer program product embodiments herein may embody algorithms and processes not specifically shown or described herein that are useful for implementation. Such algorithms and processes may include conventional utilities that are within the ordinary skill of the image processing arts. Additional aspects of such algorithms and systems, and hardware and/or software for producing and otherwise processing the images or co-operating with the computer program product of the present invention, are not specifically shown or described herein and may be selected from such algorithms, systems, hardware, components and elements known in the art.
Priority is claimed from commonly assigned, copending U.S. provisional patent application Ser. No. 61/708,846, filed Oct. 2, 2012, entitled “RAPID FRAME-RATE WIRELESS IMAGING SYSTEM”, in the name of William J. Sehnert et al., the disclosure of which is incorporated by reference.
In addition, while a particular feature of an embodiment has been disclosed with respect to only one of several implementations or embodiments, such feature can be combined with one or more other features of the other implementations and/or other exemplary embodiments as can be desired and advantageous for any given or particular function. To the extent that the terms “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” The term “at least one of” is used to mean one or more of the listed items can be selected. Further, in the discussion and claims herein, the term “exemplary” indicates the description is used as an example, rather than implying that it is an ideal.
The invention has been described in detail with particular reference to a presently preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. For example, the rib contrast suppression techniques that are used can be selected from any of a number of types of rib contrast suppression algorithm that is described in the literature. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.
1. A portable radiographic imaging apparatus for fluoroscopy comprising:
- a wheeled transport frame;
- a C-shaped support arm mounted on the frame;
- radiation sources attached to a fixed end of the support arm;
- a radiation detector attached to a retractable end of the support arm when the retractable end is extended outward from the support arm, the retractable end opposite the fixed end, wherein the radiation sources comprise two or more radiation sources that are individually energizable to emit a radiation beam toward the retractable end, the imaging detector is removable from the retractable end for free-standing operation, and wherein the retractable end is configured to retract into an interior space of the support arm;
- a rotatable switching actuator that is configured to replace one of the radiation sources by simultaneously rotating into position a new radiation source while rotating out of position said replaced one of the radiation sources and to align the radiation beams from each of the new and replaced radiation sources along the same optical path;
- a temperature sensor that provides a signal indicative of a temperature near an energized radiation source; and
- a processor configured to monitor the signal from the temperature sensor, and to control energization of the two or more radiation sources according to the monitored signal.
2. The portable radiographic imaging apparatus for fluoroscopy according to claim 1, further comprising a collimator, wherein the processor is configured to detect an orientation of the radiation detector relative to one of the radiation sources and to adjust an aperture of the collimator to shape the radiation beam for incidence on a predetermined area of the radiation detector.
3. The portable radiographic imaging apparatus of claim 1, further comprising a collimator having an aperture to shape an x-ray beam emitted by the radiation sources, the collimator including a plurality of collimator blades to define a non-rectangular shape of the aperture.
4. The portable radiographic imaging apparatus of claim 1, wherein the radiation detector is configured to capture radiographic images at a rate greater than one image per second.
5. The portable radiographic imaging apparatus of claim 1, wherein the processor is further configured to wirelessly communicate with the radiation detector, and wherein the radiation detector comprises a wireless transmitter to transmit radiographic images to the processor.
6. The portable radiographic imaging apparatus of claim 1, wherein the retractable end comprises jointed sections that telescope inward and outward, and wherein the detector and radiation source cooperate to expose and acquire radiographic image data according to a synchronization signal.
7. The portable radiographic imaging apparatus of claim 1, wherein the retractable end is configured to retract automatically when the radiation detector is removed therefrom.
8. A portable radiographic imaging apparatus comprising:
- a transport frame having wheels to rollably transport the portable radiographic imaging apparatus;
- a C-shaped support arm mounted on the transport frame;
- radiation sources attached to a fixed end of the support arm;
- a radiation detector attached to a retractable end of the support arm, the retractable end of the support arm opposite the fixed end of the support arm; and
- a rotatable actuator attached to the fixed end of the support arm, the rotatable actuator configured to replace one of the radiation sources by simultaneously rotating into an imaging position a new radiation source while rotating out of the imaging position the replaced one of the radiation sources, and to align the radiation beams emitted from each of the new and replaced radiation sources along the same optical path when in the imaging position.
9. The portable radiographic imaging apparatus of claim 8, wherein the radiation sources comprise two or more radiation sources that are individually energizable to emit a radiation beam toward the retractable end.
10. The portable radiographic imaging apparatus of claim 8, wherein the imaging detector is removable from the retractable end for free-standing operation.
11. The portable radiographic imaging apparatus of claim 10, wherein the retractable end is configured to retract into an interior space of the support arm.
12. The portable radiographic imaging apparatus of claim 8, further comprising a temperature sensor configured to provide a signal indicative of a temperature near an energized radiation source.
13. The portable radiographic imaging apparatus of claim 12, further comprising a processor configured to monitor the signal from the temperature sensor, and to control activation of the radiation sources in response to the monitored signal.
14. The portable radiographic imaging apparatus of claim 8, further comprising a collimator having an adjustable aperture to shape the radiation beams emitted from the radiation sources for incidence on a predetermined area of the radiation detector.
15. The portable radiographic imaging apparatus of claim 14, wherein the collimator comprises individual collimator blades configured to define a non-rectangular shape of the adjustable aperture.
16. The portable radiographic imaging apparatus of claim 8, wherein the radiation detector is configured to capture radiographic images at a rate greater than one image per second.
17. The portable radiographic imaging apparatus of claim 16, wherein the radiation detector comprises a wireless transmitter to transmit the captured radiographic images wirelessly during free-standing operation.
18. The portable radiographic imaging apparatus of claim 8, wherein the retractable end of the support arm comprises telescoping extendable and retractable sections that extend inward and outward.
19. A method of operating a portable radiographic imaging apparatus, the method comprising:
- attaching an adjustable support arm to the portable radiographic imaging apparatus;
- attaching radiation sources to a first end of the support arm;
- transporting the portable radiographic imaging apparatus to a position adjacent a patient in a bed using wheels attached to the portable radiographic imaging apparatus;
- positioning a radiation detector on one side of the patient;
- adjusting an imaging position of a first one of the radiation sources to align a central axis of a radiation beam emitted by the first one of the radiation sources toward the detector; and
- simultaneously rotating into the imaging position a second one of the radiation sources while rotating out of the imaging position the first one of the radiation sources, and aligning a central axis of a radiation beam emitted by the second one of the radiation sources with the central axis of the radiation beam emitted by the first one of the radiation sources, wherein the first and second radiation sources are rotated about a common axis.
20. The method of claim 19, further comprising attaching the radiation detector to a second end of the support arm opposite the first end of the support arm before the step of positioning the radiation detector.
U.S. Patent Documents
|6106152||August 22, 2000||Thunberg|
|6208706||March 27, 2001||Campbell et al.|
|7120231||October 10, 2006||Spahn|
|7906770||March 15, 2011||Otto|
|8767909||July 1, 2014||Vogtmeier|
|8971493||March 3, 2015||Zhang|
|20040057552||March 25, 2004||Collins|
|20040066907||April 8, 2004||Fadler|
|20050054915||March 10, 2005||Sukovic et al.|
|20110013220||January 20, 2011||Sabol et al.|
|20110051895||March 3, 2011||Vogtmeier et al.|
|20110080992||April 7, 2011||Dafni|
|20110158385||June 30, 2011||Nakatsugawa et al.|
|20120230473||September 13, 2012||Stagnitto et al.|
Foreign Patent Documents
|103 20 862||December 2004||DE|
|0 998 173||May 2000||EP|
|2 967 343||May 2012||FR|
|WO 2005013828||February 2005||WO|
|WO 2010070560||June 2010||WO|
- International Search Report dated May 6, 2014 for International Application No. PCT/US2013/062823, 3 pages.
Filed: Oct 1, 2013
Date of Patent: Sep 18, 2018
Patent Publication Number: 20150223767
Assignee: Carestream Health, Inc. (Rochester, NY)
Inventors: William J. Sehnert (Fairport, NY), Samuel Richard (Rochester, NY), John Yorkston (Penfield, NY), Xiaohui Wang (Pittsford, NY)
Primary Examiner: Irakli Kiknadze
Application Number: 14/430,561
International Classification: A61B 6/02 (20060101); G21K 4/00 (20060101); A61B 6/00 (20060101); A61B 6/06 (20060101); G21K 1/04 (20060101);